Hoefer HE33 User Manual page 14

Note: To calculate the voltage
gradient, divide the voltage
setting by the distance
between the electrodes
(12.7 cm).
p10
•
Quick, high-voltage runs
Certain applications, such as screening samples or
checking sample purity, can be accomplished quickly
under high voltage conditions. Chill the base (-20 °C)
and limit the run to 5 minutes or less at 500 V.
Slower, lower voltage runs
A voltage gradient of 12 V/cm (150 V) separates 0.1
to 23 kb fragments of a Hind III digest of λ DNA
in 30 to 40 minutes (using 1% agarose gel and
0.5X TBE running buffer). Alternatively, using the
same solutions, this sample could be run at 24 V/cm
(300 V) with acceptable band resolution in 20 to 30
minutes. Chill the base before use.
Table 1:
Voltage settings and recommended run settings
voltage gradient
(V) (V/cm)
500 40
400 31
300 24
200 16
150 12
*For rapid runs of 20 minutes or less, use 0.5X TBE and chill
the base to -20 °C before use.
† Voltage and times are for 1% Agarose NA, 0.5X TBE and a
chilled base.
After the separation

Turn off the power supply, disconnect the leads, and
remove the lid.

If no ethidium bromide was added to the gel or
sample before the run, stain the gel in a solution of
0.5 to 1.0 µg/ml ethidium bromide in water or buffer.

Clean the unit as described below.
†
time
(min)
5*
10*
20*
30 to 40
30 to 60